Extract from the article Blue Cube in Siena
[ … Large strip windows of varying heights interrupt the horizontal plane of the once-dominant structure. The interaction of both elements presents observers with a dynamic effect of light and shadow.
The structure of the façade sustains this optical illusion of depth. The architect makes use of two contrasting materials: much of the building is covered with a layer of dark blue plaster, hence the building’s name: Blue Cube… ]